code: def initialise_grid_aggregator(self):
      self.output_decoder = GridSamplesAggregator(
          image_reader=self.readers[0],
          output_path=self.action_param.save_seg_dir,
          window_border=self.action_param.border,
          interp_order=self.action_param.output_interp_order,
      )
  
imports: import tensorflow
  from niftynet.application.base_application import BaseApplication
  from niftynet.contrib.segmentation_selective_sampler.sampler_selective import SelectiveSampler, Constraint
  from niftynet.engine.application_factory import ApplicationNetFactory, InitializerFactory, OptimiserFactory
  from niftynet.engine.application_variables import CONSOLE, NETWORK_OUTPUT, TF_SUMMARIES
  from niftynet.engine.sampler_grid_v2 import GridSampler
  from niftynet.engine.windows_aggregator_grid import GridSamplesAggregator
  from niftynet.io.image_reader import ImageReader
  from niftynet.layer.binary_masking import BinaryMaskingLayer
  from niftynet.layer.discrete_label_normalisation import DiscreteLabelNormalisationLayer
  from niftynet.layer.histogram_normalisation import HistogramNormalisationLayer
  from niftynet.layer.loss_segmentation import LossFunction
  from niftynet.layer.mean_variance_normalisation import MeanVarNormalisationLayer
  from niftynet.layer.pad import PadLayer
  from niftynet.layer.post_processing import PostProcessingLayer
  from niftynet.layer.rand_flip import RandomFlipLayer
  from niftynet.layer.rand_rotation import RandomRotationLayer
  from niftynet.layer.rand_spatial_scaling import RandomSpatialScalingLayer
label_desc: Use image node_id 5 for calling the SelectiveSampling obj's underlying member method code with example usage: obj.initialise_grid_aggregator() without return types